LOSSES TO CORN 



B 608 
112 W4 
Jopy 1 



What to Look For 

and 

Where to Find It 



Being one of a series of articles in relation to crops, their common 
diseases, and insect pests to which they are subject 




Published by 

HAIL DEPARTMENT 

Western Adjustment & Inspection Go. 
CHICAGO 



LOSSES TO CORN 



/<*& 




LOSSES TO CORN 



What to Look For 

and 

Where to Find It 



Being one of a series of articles in relation to crops, their common 
diseases, and insect pests to which the.v are subject 




Published by 
HAIL DEPARTMENT 

Western Adjustment & Inspection Co. 
CHICAGO 






Copyright, 1919, W. E. Mariner 



FEB -6 1919 

>CI.A5I J 488 



Strotnberg, Allen & Co., Chicago. 

Printers 



AN ARTICLE RKLATING TO 

CORN 

Describing, in common terms, the nature and deli- 
cate characteristics of that all-important food cereal. 

Some expressions are added as to its predatory 
enemies — plant diseases and insect pests. 



''While there is no country in the world that can 
teach American industry much, there is likewise not a 
country which cannot teach American agriculture 
something. The time for us to learn grows shorter 
and shorter. "We can no longer go from the depleted 
held to the virgin tield. We must have a hetter agri- 
cultui-e." — Gov. Frank 0. Lowden (Illinois). 



FOREWORD 

This is the first of a series of articles we hope to issue 
in relation to cereal crops, their common diseases, and insect 
pests to which they are subject. 

This treatise relates wholly to corn, but will be fol- 
lowed by others relating to oats, flax, wheat, and various 
cereal plants. 

These offerings are gratuitous, but will have been pre- 
pared with considerable care by the Adjustment Company 
in the belief that they may prove of some value to every 
institution writing hail insurance. 

Western Adjustment & Inspection Co. 

Chicago, January 1, 1919. 



INTRODUCTORY AND FOREWORD 
TO ADJUSTERS 

"He who knows what not to say, 
Holds half the secret of success." 

A successful adjuster of hail losses must be diplomatic, 
even-tempered, and well informed on agricultural topics. 

The really successful adjuster is the one who is able 
to induce the impression that he is representing both the 
company and the claimant, and whose sole aim is effi- 
ciently and correctly to establish the true measure of loss 
without fear or favor. 

He must determine whether climatic conditions have 
retarded the crop, whether improper farming methods have 
contributed to the loss, and whether insects and diseases 
have caused any part or all of the claimed damage. He 
must know whether or not animal enemies have been at 
work; that is, he must quickly and surely separate the other 
losses from that for which the company is properly liable, 
demonstrating conclusively to the claimant that he is a dis- 
interested neutral with the sole aim to deal fairly and intelli- 
gently for the two principals to the insurance contract. 

He should so thoroughly educate himself in practical 
farming that he can helpfully and intelligently advise, when- 
ever his counsel is sought, disseminating his information in 
a spirit of friendly helpfulness ; for this is an era of prog- 
ress, and increased production is vitally necessary to the 
future welfare of the nation. The farm is the source of our 
food supply, and anyone who can, by timely counsel, assist 
a farmer toward more careful and scientific methods bene- 
fits not that one man alone, but all mankind. 

With the world crying for food, slack and careless 
methods of farming border closely on criminal negligence. 

This is a progressive age. Particularly is this true 
of farming. Conditions of husbandry are changing rapidly. 
The farmer himself is changing to a new type — one that 
maintains a position on a level with other professions. He 
is not the ''havseed" at whom his city cousin poked fun 



twenty years ago. By far the greater proportion of farm- 
ers are edneatecl, well and widely read, and eager to add to 
their knowledge. 

Competition caused by increased vahies of land and 
labor are the primary causes of the farmer's advancement 
in scientitic agriculture. He has found that increasing his 
knowledge of crop enemies heli)s him to hold and retain his 
position in the agricultural world and returns as well a 
handsome jDrofit in the way of increased yields. 

The improved methods and conditions on the farm are 
largely due to the educational work carried on by the 
United States Department of Agriculture, the agricultural 
colleges and experimental stations, the various agricultural 
societies, and the farm press. 

Millions of dollars are being expended annually by 
these institutions in the interest of better farming. They 
are furnishing the farmer with an abundance of most valu- 
able information on such subjects as soil management, seed 
selection, crop rotation, destruction by crop enemy insects, 
crop diseases, and kindred subjects, and the farmer who 
does not avail himself of these advantages is overlooking a 
source of most useful and helpful learning. 

Crop insect and disease bulletins by the thousands are 
printed every year. An increasing number of farmers are 
diligent readers of these pamphlets, which contain many 
practical suggestions. Other suggestions are not so help- 
ful, and for the individual to grope through them all, en- 
deavoring to sort out the really good ideas, often consumes 
more valuable time than the returns warrant. For this 
reason, the bulletins are frequently ignored or carelessly 
read. 

With this in mind, we have i)repared this little book for 
our hail adjusters as an outline study and a ready field ref- 
erence. 

We have endeavored to include only those causes of 
loss most frecpiently encountered in our territory, and treat- 
ment of them has been condensed as much as possible in 
order that adjusters may not be burdened with a needless 
groping through masses of irrelevant discussion or tedious 
detail interesting only to an entomologist. 

Some of the infrequent conditions of loss are not in- 
cluded, as they are of such unusual occurrence or cause 



such insii^nificant damage that it is needless to encumber 
this article with them. Likewise descriptions of some few 
diseases and insect enemies, closely related and of almost 
identical habits of destruction, are combined. To discuss 
them separately would reipiire the finest entomological dis- 
tinctions and these seem unnecessary for our purposes. 

Should information concerning any of the unrecorded 
conditions be desired, we are prepared immediately to fur- 
nish complete data to all adjusters in any affected district. 
Unknown or unusual causes of loss should be reported to 
our head office, with complete description and samples of 
grain or of insects encountered. The special subject will 
then be analyzed and a sui)i)lemental bulletin issued. 

Any measures tending to increase the adjuster's fund 
of information are valuable because, of the many pre- 
re(juisites to successful dealing with farmers, the most im- 
portant is knowledge of agriculture. 

It is impossible to know too much on that subject. Our 
adjusters add to their efficiency by increasing their knowl- 
edge of crops. There is where the quality of work shows. 
Agriculture is a big subject — it is impossible for any one 
man to know all about it — but the more of it known> the 
more valuable will be this service. We wish to spread this 
viewpoint. 



PART ONE 

INSECT ENEMIES 

Aside from the dangers of improper farming methods, 
the uncertainties of climatic conditions, and the ravages of 
diseases against which tlie struggling corn plant must fight 
its way to a successful maturity, there are 214 species of 
insects injurious to the corn crop. We have not attempted 
to describe them all or even to enumerate them here, but 
liave included those most injurious and most frequently 
encountered throughout the corn-growing districts. 

Explanation of Terms 

Larva — Caterpillar or worm stage. 
Pupa— Cocoon or resting stage from which the adult 
emerges. 

Cornstalk Borer 

The cornstalk borer is about an inch long when full 
grown. Its color varies from purplish to whitish brown, 
according to age, and it is marked with five white stripes 
— one running down the middle of the back, and two 
on each side. These side stripes are interrupted, being ab- 
sent on the first four segments of the abdomen, giving the 
larva an appearance of having been pinched or injured 
there. The stripes nearly vanish as the larva matures. 
The head and top of the neck and the leathery anal shield 
at the o|)posite end of the body are light reddish yellow, 
with a black stripe on each side. 

The i:)resence of the cornstalk borer in a young stalk 
of corn is very clearly indicated by the wilting, breaking 
down, and death of the top and by the presence of a round 
hole in the side of the stalk plugged with the l)rowii excre- 
ment of the caterpillar within. 

The borer infests a great variety of plants in a pre- 
cisely similar way. It is most noticeable in early si)ring in 
bluegrass by roadsides or around the borders of a field, its 
presence being indicated by the whitening of single heads 
while all the rest of the plant is green. At this time it is 
of small size and finds sufficient food within the grass stem ; 

10 



but later it is compelled to resort to thicker-stemmed plants, 
and it is then that it appears in fields of corn. 

The burrow which the stalk borer makes within the 
stem runs upward from the entrance opening, and of 
course varies in size with the growth of the larva. Some- 
times in leaving a stalk it makes a new hole above the one 
by which it entered, and it may in this way burrow in suc- 
cession several different stalks. 




CORNSTALK BORER. 

Larva, in the lower part of corn plant, eating away the heart of the stalk, 
light hailstorm accompanied by wind will give the field the appearance 
of having been heavily damaged by hail. 

11 



Corn is injured by this pest while from two to ten 
inches high. Tliis is only one of several insects which pro- 
dnce the same general etfect, but its depredations may be 
at once distingnislied by the ronnd hole which it leaves in 
the stem of the infested plant. Its work is largely within 
the stem and is so concealed that in most cases, unless 
weather conditions make it conspicuous, the presence of the 
insect passes unnoticed. 

Corn is damaged by these caterpillars in two ways. 
First, in the early part of the season, while the plants are 
small, they work in the ' ' throat ' ' of the young corn, and if 
the tender growing tip within the protecting leaves is once 
damaged the ]ilant will not become a normal productive 
specimen. In many sections of the South this is commonly 
known as "bud-worm" injury, and though there are sev- 
eral other insects which cause a similar mutilation of the 
leaf, a very large proportion of the so-called "bud-worm" 
damage may be charged to this insect. The etfect of its 
work on the leaves of the young corn ])lants is similar to 
that resulting from attacks by the corn bill bugs and is evi- 
denced by the familiar rows of small circular, or irregular, 
holes across the blades of the plant. 

The Corn Bill Bug 

When growing corn is but a few inches high the tender 
leaves are often injured by rows of holes cut across the 
blade by the corn bill bug; when severe, the injury causes the 
growing plant to be greatly stunted. This kind of injury is 
most likely to occur when corn directly follows timothy sod. 
It is therefore well to determine what kind of crops were 
produced on the field the previous year when a supposed hail 
damage bears a resemblance to the work of the corn bill bug. 

When corn is starting in the spring this beetle will cling 
to the young, tender stalks, with head downward, and eat 
its way into and often through the center of the stalk. 
This kills most of the plants, but when corn survives the 
attack the leaves will bear from two to five holes, all in 
a row. The injured blade is still within the sheath of 
the stalk when the damage is done, and the holes do not 
become noticeable until after the blades grow out. It is 
therefore evident that a corn plant can be injured by the 
bill bug and the damage thus caused may easily be con- 

12 



fused with hail damage after the blade has grown from the 
sheath, which may take from a week to ten days. 

The corn bill bug is a snont-beetle, varying from tive- 
sixteenths to six-sixteenths of an inch in length. 

There are several kinds of bill bugs. Most of them 
are black or brown in color. One kind is clay colored. 
All are beetles with hard backs, and with a long snout with 




THE CORN BILL BUG. 

Showing how it eats the leaves of young plants. If a few additional holes were 

added to this plant by hailstones, the grower might contend 

that the whole visible damage was caused 

by hail. 

13 



wliicli the holes in the corn blades are made. The larvae 
usually feed on the roots of certain grasses, largely on tim- 
othy roots. Hence when corn has been planted on timothy 
sod that has been infested with these grubs, the mature bill 
bugs are very likely to attack the corn as soon as it api^ears 
above the ground, especially if the sod is turned under in 
the spring. 

Unless the leaves have been badly stripped by hail, 
showing conclusive evidence of hail damage, a close exami- 
nation of the plants should be made for evidence of the 
bill bug. 

White Grubs 

The young of the May beetles are capable of devastat- 
ing and frequently destroying large portions of farm crops 




DEFOLIATED TREES. 

Walnut and soft maple, the former defoliated by May beetles. They much 

prefer corn leaves. 

by eating the roots. The crops damaged include two of our 
most important staples, namely, corn and potatoes. The 
adults — the beetles — often becomes so ravenous that they 
also eat the leaves of certain trees. 

14 



These insects require three years to complete their life 
cycle, and usually only one brood is destructively active in a 
given locality. An abundance of May beetles one year 
presages a large growth of grubs the following season. 

It should be remembered that injury from white grubs, 
as well as from many other pests, may be forestalled by 
correcting farm practices ; but after corn, or any field crop, 
has become infested it is impossible to prevent further in- 
jury to that particular crop for the current season. 




WHITE GRUBS. 
Showing the 3-year period of their cycle life. 

In the worst infested districts it is not unusual to tind 
from 40 to 60 white grubs in a single hill or corn. Indeed, 
in a cornfield near McGrregor, Iowa, which had been planted 
to timothy the previous year (1917), 77 two-year-old grubs 
were found in an area only 2^ feet square and 5 inches 
deep. This really represented an area less than that usu- 
ally occupied by a single hill of corn, for the hills in this 
field were 3^ feet apart. 

Wireworms 

Injury to corn by wireworms occurs in the s])ring soon 
after planting. The failure of seed to sprout, or the dying 
or withering down of corn plants about two feet or less in 
height, both indicate wireworm attacks. If a field so 
affected has been in grass a year or so previously, any 
injury is most likely to be that of wireworms. Although 
the larvae do not cause any injury to grass, when such 
land is put into corn the wireworms concentrate on the 
hills of the planted grain, causing much damage. 

15 



"Wireworms feed first on the seed itself, later on the 
roots, eating the smaller ones entirely and boring or pene- 
trating- the larger ones. 




THE CORN WIRE WORM. 

1, 3, 4, 5 — Types of the click beetle, adult of the corn wireworm. 
2 — The corn wireworm. 

16 



The common corn wireworms are reddish brown in 
color, hard and rather shiny in appearance, cylindrical in 
shape, and an inch or more in length. 

Quite frequently these worms do not attack the plants 
nntil these are six inches or more in height. 

A slight hailstorm upon a field of corn wiiere these 




CORN ATTACKED BY WIREWORMS. 

Note the thin stand and stunted growth of the phmts. The grower might 

claim that hail caused a set-back to this crop, but the wireworms know better. 

They do not need any outside assistance to make a crop failure here. 

worms are at work will enlarge the claimed damage caused 
by the hail, the farmer insisting that hail caused the whole 
loss. 

Close observation of adjoining fields and also of the 
roots of damaged plants will help to determine whether 
any loss has really been caused by hail. If wireworms are 
working on the plants they will be found on the roots, not 
of the dead plants but of those which are, to all outward 
appearances, in sound health. 

The appearance of the dead plant is identical, whether 
the damage has been caused by hail, water, or wireworms. 

17 



The Chinch Bug 

Damage to corn occurs, for the most part, in mid- 
summer when the growing bugs pass from ripening wheat 
to corn. It does not necessarily follow that the chinch bug 




THE CHINCH BUG. 

1, Larva; 2, 3, 4, 5, and 6, various sizes, enlarj 
A and B. Showing bugs on stalks. 

18 



will not become dangerous in localities where no wheat is 
grown. On the contrary such is likely to be the case. 

This abominable insect, one of the very worst enemies 
of agriculture, is, on the whole, the most destructive to 
corn of all the insect species to whose attack this crop is 
subject. 

It is estimated that the total agricultural losses due to 
the ravages of this insect have amounted in single states 
to from ten to twenty million dollars in a season, and 
throughout the whole habitat of this insect enemy, to a 
hundred million dollars or more in a single year. 

The ravages of this insect are due to the sucking of the 
sap from the plants. Being without jaws for biting, it can 
appropriate only fluid food by piercing the tissues of the 
plant with the hair-like stylets of its beak and then sucking 
the sap from the lacerated cells. Owing to its immense num- 
bers, it may so rapidly drain a strong and thrifty corn 
plant, a foot or two in height, that the plant will wither and 
fall to the ground as though cut otf at the root. 

At harvest time the young of the new generation are 
in various stages of development, owing to the fact that the 
eggs are laid at intervals during a period of about a 
month. There are at wheat harvest some winged bugs in 
the field, but the great majority of them are of ages varying 
from those just hatched up to the stage preceding the last 
molt. Forced out of these fields of small grain by the ripen- 
ing of the plants and consequent possibility of starvation, 
the bugs enter fields of oats and corn in a continuous throng, 
making their migration wholly on foot. They thus concen- 
trate in overwhelming numbers on the plants at the borders 
of the newly entered field, draining and killing everything 
as they go. It is at this time that the principal injury to 
corn is done. 

The effect on corn varies with the extent of the attack. 
The work of destruction is thorough, and often, even in 
the migratory movement, every plant in several rows will 
be killed. The bugs move forward across the fields, attack- 
ing row by row, leaving scarcely a living stalk behind, and 
often ruin entire fields of 50 or 60 acres. 

19 



CUTWORMS 

Cutworms are most damaging to corn when corn fol- 
lows sod. Tlie injury to young corn plants is known to 



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CUT WORM AT WORK ON STALK OF CORN. 

most farmers, but tlie results of tlie work of cutworms are 
so similar to liail injury that the damage is often confused 
with that done l)v a hailstorm. 



20 



This injury should not be confused with that done by 
other corn pests. Usually the insect responsible for the 
damage may be found in the soil near the plant attacked. 

Invariably, when a cornfield has been visited both by 
cutworms and a hailstorm, the farmer is likely to claim that 
the hail was responsible for all of the damage incurred, 




THE CUTWORM. 

A. Larva in characteristic position. B. Head 

(Greatly enlarged.) 



of larva. C. Adult moth. 



when as a matter of fact cutworms by the thousand are 
destroying the plants. 

A damaged plant has the appearance of having been 
cut off by a hailstone, and the only certain way to deter- 
mine the exact cause is to locate the cutworm and call it to 
the attention of the claimant. 

Full-grown cutworms are about one and one-half inches 
long, usually dull in color. They work on the young plants 
at night, and during the day they will be found on, or near, 
the corn roots asleep. 

21 



The Corn Root Worms 

There are two species of root worms, to wliich tliree 
names are applied; namely: northern, western, and south- 
ern. The first two refer to the same pest. The southern 




CORN ROUT \\ ORM DAiMAUE. 

The corn root worm was responsible for this crop faihire. The field was only 

partly infested by the worms. Note quality of i)lants where the worm 

has not molested the crop. The entire field was 

planted the same day. 

variety is slightly different. The depredations of the corn 
root worms are very similar to, and easily confused with, 
hail damage. 

Their presence in a field is usually indicated by a with- 
ering of the young plants, the failure to produce well- 
developed ears, or a general retarding of the growth with- 
out visible cause. A search among the roots of such stalks 
may bring to notice the tiny root worms. 

The root worms themselves are small, slender white 
grubs, about half an inch long when they are full grown. 
Infested stalks of corn may be pulled out easily and will 
break off at the place where the root worms are at work, 

22 



leaving the greater part of the roots in the soil. Frequently 
infested stalks are blown to the ground by wind, the root 
system having been so cut off that the stalks cannot stand 
the strain. 




THE CORN ROOT WORM. 
Showing the worm at work in corn root. (Enlarged.) 




NORTHERN CORN ROOT WORM. 
1. Larva; 2. Beetle; 3, 4, 5, and 6. Corn roots eaten by the worm. 



Shortly after midsummer the root worm becomes full- 
fledged, pupates, and emerges as a grass-green beetle. This 
beetle feeds on the silk at the top of the ear, and when this 
dries works its way down inside the husk and feeds upon the 
corn itself. Before the beetles die they leave the corn and 
lay their eggs in the ground. The eggs hatch in the spring, 
and the life cycle is thus completed. 

23 



The beetles of the southern root worm are larger than 
those of the other species and have three transverse rows 




SOUTHERN CORN ROOT WORM. 

1. Egg; 2. Larva; 3. Pupa; 4. Beetle; 5. Infested stalk. 
A. Showing where larva entered stalk. 

of four black spots on wing covers. Both species live wholly 
on corn, harming no other plants so far as is known. 

The Corn Ear and Leaf Worm or Boll Worm 

This is the common greenish or brownish "worm" that 
eats into the ears of both field and sweet corn. The eggs 
are laid usually in the silk of the ear, and the young larva 
soon begins to feed, eating into the grains of corn at the 
tip of the ear. As it grows it tunnels down toward the butt 
end, eating only a part of the corn, yet injuring the whole 
ear so far as market purposes are concerned. 

It sometimes feeds on the leaves, causing heavy damage 
to the plant by destroying the canals and tissues. 

The corn ear worm spends the winter in the pupa state 



24 



in the ground. Sometimes in late spring, in May or June, 
the adult moths emerge and dej^osit their eggs on the corn. 
If the weather is favorable during the first half of Septem- 
ber (mild), these larvae may still be found, eating on the 
ears and leaves. 




THE CORN EAR WORM. 

Showing the destructive hirva at work in ear of corn. 

Mature larvae measure about one and one-half inches 
in length. The moth, a rather stout insect, measures three- 
fourths of an inch in length. 

The larvae vary in color from light green to brown^ 
being more or less striped in appearance, with alternating- 
light and dark lines. 

25 



In the South they are called "boll worms," as they also 
feed on the bolls of the cotton plant. 




THE CORN EAR WORM. 

Showing larva at work on blades of corn. When it does this injury it is 
sometimes known as the "shattleworm." 

Corn Root Web Worm 

Corn root web worms are the larvae of several species 
of moths. Their eggs are laid in the summer among the 
grasses, and, ordinarily, injury is to be encountered only 
where corn follows grass. The larvae pass the winter in 



26 



a half-grown condition and attack the young corn jnst above 
the gronnd. When not at work they remain in a silken web 
jnst underneath the ground at the base of the plant. Their 
name is derived from this habit. The full-grown larvae are 
about half an inch long, varying in color from brown to dirty 




VARIOUS STAGES OF THE WEB WORM. 

white. Ordinarily they work at the roots of the corn plant, 
but are often found farther up the stalk working beneath 
their protective web, feeding upon the foliage and some- 
times devouring the whole leaf. 

They pupate from May to July, depending on locality, 
emerging into the moth stage. There are several broods 
each year. 

The Corn Root Louse 

The corn root louse is a small bluish-green insect. 
There are both winged and wingless types. Eggs are laid 
by the lice during September and (3ctober in ant hills, are 
collected by the ants and cared for through the winter. In 
spring when the lice begin to hatch, the ants tunnel to the 
roots of the corn and carry the young insects to them. The 
lice are equipi)ed with tiny beaks and feed upon the stalk of 
the plant, hanging to the roots in clusters, robbing the roots 
of the food necessary to sustain the stalk and leaves of the 
plant. 

Their presence can be determined by pulling or digging 
up the plant, a careful inspection of which will reveal the 
bluish-green particles. The affected plants appear yellow 
and sickly and grow very slowly, or not at all. The lice do 
their greatest injury during May and June, and their attacks 
are usually in spots throughout the field adjacent to the ant 

27 



hills. The mjiiry done by these insects is variable and 
irregular, and they may be found in one locality while 
another quite close is entirely free from them. This is 




CORN ROOT LOUSE. 

Winged and wingless varieties of the corn root louse. 
(Greatly enlarged.) 

due, doubtless, to the fact they have many enemies which 
prey upon them, and they cannot thrive if these foes are 

The Corn Plant Louse 

The corn plant louse is closely related to the corn root 
louse, which it resembles. Its work is confined entirely 
to the plant above ground, and it is less injurious than the 
root louse. The general appearance and habits of the two 
are so very similar that it is unnecessary to go into more 
detailed description. 

28 



PART TWO 

DISEASES ;. 

Corn lias been generally considered less subject to 
attacks of fungous disease than other grain crops because 
there have been no widespread epidemics as with wheat, 
in the case of which rust sometimes destroys the entire crop 
over an extended area. However, such attacking diseases 
as corn smut and other bacterial diseases of corn are well 
known and have always caused serious damage. 

Stalk Fungus 

This disease is characterized by falling of the corn, the 
stalks breaking close to the joints. Affected plants contain 




FUNGUS INFECTION. 
Diseased stalk, showing manner of breaking at lower part of stalk. 

29 




30 




31 



only small ears or are barren. When a grower's atten- 
tion is called to' this condition, the rejoinder is usually made 
that the stalks were broken over by hail. 

The disease attacks the roots and stalks. In some 
instances its intrusion has been so severe that entire fields 
of corn have been broken flat to the ground. 

In some fields 10 stalks out of 22 were attacked ; in one 
field, 23 out of 26 were involved. In one upland field of 
corn, considered a good stand, 41 per cent of the plants 
were attacked, and the yield was a little over one-half of a 
normal crop. In many other fields the loss was only one- 
third of the crop. Without some knowledge of this disease 
one might easily confuse the damage to the crop with that 
caused by hail. 

These fungus germs are capable of living through the 
winter either in manure piles on diseased ground or on 
diseased stalks left in the field. There is no known cure or 
preventive except a careful selection of seed from healthy 
plants taken from parts of the field where no fungus has 
made its appearance. 

The accompanying photographs (pages 30, 31) showing 
a field of corn where this disease has attacked the stalks, 
together with a cornfield that has been hailed, give an illus- 
tration of similarity of damage caused by two different corn 
enemies. 

Ear Scab or Ear Rot 

There are four infections of corn ears which are com- 
monly referred to as scab or rot. The damage done is some- 
times claimed as that of hail, but where an ear is hit by a 








CORN EAR ROT. 
Showing effect of fungi on corn ear, commonly referred to as scab or rot. 

32 



hailstone hard enough to cause rot the impression in the 
outer husk is sufficiently marked so that no confusion should 
result. 

Smuts of Corn 

Smut diseases of corn are so evident and well known 
that it is impossible to confuse this condition with hail 
damage. Hence no further identification need be made here. 
The accompanying photograph illustrates the smut attack 
on the ear and tassel. 




THE CORN SMUT ON EAR. 

When ears of corn are affected in this manner the result is nothing short of a 

total loss. 



33 



PART THREE 



CAUSES OF LOSS TO CORN OTHER THAN INSECT 
OR DISEASE CONDITIONS 

Aside from insects and disease conditions which occa- 
sion a very considerable loss to corn, there are numerous 
other causes for a material reduction of yield or a complete 
failure of the crop. Knowledge of the elementary principles 
and processes of corn culture is therefore essential to the 
intelligent handling of these losses. 

Any disregard of the fundamentals, in attempting to 
produce corn, is likely to result in a loss, as of all the 
cereals it is most affected by adverse conditions. 

Corn requires a better soil than do other cereal crops, 
and is most susceptible to injury by unfavorable climatic 
changes. It grows best on deep, fertile soils in warm moist 
climates, and needs frequent showers and plenty of sun- 
shine. It is especially liable to injury by drought and hot 
winds when it is silking and tasseling and from the time 
the ears first show silk until they are past the roasting- 
ear stage. 

If the correct practices of corn-growing are not 
observed, a weakened stalk is produced which can neither 
overcome unfavorable weather conditions nor successfully 
combat insect or disease enemies ; and while these foes show 
no preference between a sick and a healthy plant, a hardy 
stalk, growing from pure seed, fortified with a cluster of 
strong roots and firmly imbedded in a jiroperly prepared 
and carefully cultivated seed bed, will survive long after the 
unhealthy weakened plant has succumbed. 

Because corn is subject to serious loss through careless 
or unintelligent farming, a summary of methods is here 
included which have a bearing on hail insurance, for spuri- 
ous hail claims are most frequently rei)orted in those sec- 
tions where midsummer drought, hot winds, poor soil, and 
indifferent farming practices prevail. 

34 



The science of corn-growing is divided into eiglit 
processes, as follows : 

1. Seed selection. 

2. Storing of seed. 

3. Testing of seed. 

4. Preparation of seed bed. 

5. Planting, 

6. Cultivating. 

7. Harvesting. 

8. Marketing. 

A corn crop is half grown before the seed is planted, 
and, without careful attention to the first three processes, 
operations four, five, and six will be of small avail, even 
though the most approved methods are applied with ]iains- 
taking care, and seven and eight either will never be 
realized or will be attended with disappointment because of 
unsatisfactorv results. 



35 




RESULTS OF IMPORTED SEED. 




RESULTS OF ADAPTED SEED. 

Note the comparatively more vigorous growth of the stalks and the larger size 
of both stalks and ears. 



36 



Seed Selection 

"There is just one worse way to select seed corn 
than to pick it from the crib in the spring', and that 
is to pick it from a neighbor's crib after dark." 

The unescapable result of poor seed is either a kernel 
that does not germinate or a weak sickly plant which, true 
to the governing' law of plant life, produces a nubbin instead 
of a well-filled ear of marketable corn. 

The character of the seed used is therefore a most 
important factor in the production of a large corn crop, and 
especially because it is so likely to be defective. Selection 
of fertile soil, good cultural methods, and protection against 
insect and disease enemies are of the greatest importance 
in contributing to the final results, but all these factors 
cannot overcome indifferent seed selection. 

Experiments with unknown and imported seed are dan- 
gerous, as corn must become adapted to a general locality. 
Seed should be selected in the neighborhood in which it is 
to be planted. 

To secure a full stand of vigorous i)lants, able to combat 
unfavorable weather conditions and overcome insect and 
disease enemies up to the final production of a good crop, 
carefully selected, home-grown seed must be used. 

Many farmers overlook or ignore these important 
features, and the inevitable result is poor yield and poorer 
quality. 

When the certainty of good seed is one of the cheapest 
and simplest ways of increasing the corn crop, and when 
the farmer has the benefit of the expert advice of his state 
agricultural college offered him and even brought to his 
door by extension trains, institute meetings, and frequent 
bulletins — all free of charge — fundamentally correct meth- 
ods are too often overlooked. 

If seed of a uniform size and high germination test is 
evenly planted in a scientifically prepared seed bed on 
selected soil, and is then properly cultivated, there will be 
surprisingly few spurious hail claims, and these will be in 
evidence only when most unfavorable climatic conditions 
have prevailed over an unusual period. 

37 




WHY A CAREFUL SELECTION OF SEED CORN IS ESSENTIAL. 



3S 



Fig. 1 — These three ears came from the same hill. The difference between 
them is due to the producing power of their parents. 

Fig. 2 — Here is a remarkably well-shaped ear of corn. It has breeding and 
brains back of it. 

Fig. 3 — Scrubs or degenerates. They are always most numerous when con- 
ditions are unfavorable, such as poor ground, late planting, poor cultivation, 
careless selection of seed, etc. 

Fig. 4 — More degenerates. What happens where we have a mixture of 
different types of corn. 

The first ear was too late. The only fertilization it received was from the 
old and weak grains of pollen which blew off the leaves and tassels where 
it had lodged. 

The third ear is the result of a mixture of early and late types. Notice the 
many broken or ruptured kernels. These inherited the late characteristics 
of one of the parents and were soft when other kernels hardened and crowded 
them. The crowns broke open and have become rotten and moldy. 

The second and fourth ears are faulty because of the irregular rows and 
consequent irregular kernels. 

Fig. 5 — Broken kernels. Probably caused by a disease in connection with 
the silks, which sometimes lie between the rows of kernels as they develop. 
This condition will not be detected until kernels are removed for study, or the 
ear is shelled. 

Fig. 6— The first ear has 540 kernels, while No. 2 has 1,140, or double the 
number on ear No. 1. 

\Yhen tested in the planter, No. 1 dropped 158 kernels in 100 drops, while 
No. 2 dropped 387 kernels in 100 drops or checks. But this is not the only 
disadvantage; the yield and quality of the crop will be affected in other 
ways. There will be immature, moldy, and frozen corn, high ears and low 
ears, ears hard to husk and ears easy to husk, etc. 



39 



DO NOT IMPORT SEED COR(\l 

HOME GROWN SEED BEST 

6000 TESTS-8 YEARS-33 COUNTIES-IOWA 

YIELD 



HOME 
GROWN 


67 BU 


O L w L^ 








IMPORTED 
SEED 


47 BU 


20 BU. 
LOSS 









HOME GROWIM SEED 
GIVES LARGER YIELD BETTER QUALITY 
SAVES LAWD LABOR FOOD MOWEY 



40 



Deep Cultivation ; Its Af ter-EfFects on Growing Corn 

Twenty years a^i^o had a farmer been asked, ''Why do 
you cultivate corn?" he would probably have replied: "To 
kill the weeds." 




/\J\ Store-house in which 
'''^\ .reserve pUnt-food is 



■Pound 



l^Fcicto ry where plant- 
food is made into 
pUnt-l issue 



, — Trcinsportation system 
^\ by which pknt-food is 
carried 



■Mine from which 



~^,"-;\ i ".■•'^~^>1 cvll plant-food except 
;V} Cdrbon is obt^iined 



Note extended root system. Deep cultivation disturbs the roots and often kills 

the plant. 

41 



Ask that question now and a most general response 
wonld be, "To conserve moisture." 

Agriculturalists have learned that surface cultivation 
is of first importance, inasmuch as it brings forth best re- 
sults without disturbing the root systems of the growing 
plants. 

Corn roots intermingle between rows. Deep cultivation 
when plants are coming forth may disturb roots and, in 
some cases, break them apart, causing stalks to wilt and 
dry up, often ending in decay. 

Some growers, particularly those in wheat-raising sec- 
tions, seem to be wholly unaware of this important situation, 
even though much has been written on the subject. 

It is by no means uncommon for an assured to feel 
that a hailstorm caused a setback to his corn crop, and he 
may even point out the sickly, drooping appearance of the 
leaves to substantiate a claim. 

Deep cultivation of waist-high corn may produce a 
similar general appearance and cause the same apparent 
after-effect as that following a hailstorm. 

A planter in Kearney County, Neb., recently claimed 
a hail loss on 150 acres of corn, asking 50% on 60 acres and 
20% on the remainder of his crop. After the adjuster had 
made a careful examination, accompanied by assured, it 
was found that the claim was not exorbitant, for the corn 
plainly showed evidence of serious damage. The 50% loss, 
however, stopped on a single row of corn extending entirely 
across the field, and the 207o loss began on the next row — 
and at one end of that row stood a corn cultivator. 

The soil of the 60-acre tract showed evidence of recent 
cultivation, while the remainder of the field did not. The 
crop involved was badly infested with weeds, and the 
assured admitted that he had dropped the cultivator shovels 
below the surface of the ground at least eight inches. 

As examination of the roots of plants on the 60-acre 
field showed clearly how an additional loss had occurred, 
the farmer was convinced of the mistake made by cultivat- 
ing too deeply and readily accepted a proper and e(juita])le 
settlement for the actual hail damage sustained. 

42 



Crop Rotation for Corn 

One of the commonly neglected features of all farming- 
operations is rotation. Until the American husbandman 
learns to rotate his crops intelligently, he will have dimin- 
ished yields, inditferent quality of grain, and various loss 
conditions often, to the untrained eye, closely resembling- 
hail damage. These are caused by the ravages of insects, 
the insidious working- of various fungi, and, less frequently, 
by depleted soil. 

When corn is grown continually on the same land, this 
condition is inevitable, and in case of a possible hail damage 







€^.Jl 



. -h i^M. 



CROP ROTATION. 

Crop rotation means life to the soil and death to insects. 
The next year corn should be planted elsewhere. 

a little inquiry as to the number of consecutive years a field 
has been planted to corn may yield information as to the 
cause of damage. 

A rotation of crops is good farm practice. By growing 
different crops the planter is able to distribute his labor 
over a greater part of the year, and thus handle more 
ground with the same equipment and horsepower. There 
is less risk of a total failure for the season, since, if drought 



43 



or hail injures or destroys one crop the others may escape 
injury. 

The various experiment stations and agricultural 
colleges in tlie different states have determined the best 
scheme of rotation for their respective territories and are 
anxious to disseminate this valuable information. The 
planter alone, therefore, is responsible for all loss caused 
by lack of a correct system of cropping. 

Climatic Conditions 

Climatic conditions prevailing during the season and 
the state of weather immediately preceding a suspected hail 
damage to corn have a bearing on nearly every such claim. 

Unseasonable frosts, hot or high winds, cold rainy 
weather, hard, beating rains, or too much moisture will cause 
a most serious loss that is frequently charged to hail account 
and in fact often closely resembles hail damage. This is 
especially true if proper farming methods have not been 
followed, or if the crop is undergoing the ravages of disease 
or insect pests. 

Leaves of corn are easily whipped to ribbons by the 
wind, or the pollen is dislodged by a hard, beating rain. Hot 
winds may wither the leaves and blast the ears, and frost, 
cold rainy weather, or too much moisture cause the young- 
plants to turn yellow and wilt, much as if they had really 
been hailed. All these conditions are well known to experts. 



"To do only what you set out to do 
indicates that you did not set out to do enough." 



44 



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INDEX 

Page 
No. 

Causes of Loss to Corn Other Than Insect or Disease Condi- 
tions . .- 34 

Climatic Conditions .- 44 

Chinch Bug - - 18 

Corn BillBng 12 

Corn Ear and Leaf Worm or Boll Worm ' 24 

Corn Plant Louse -.- - - - 28 

Corn Root Louse 27 

Corn Root Web Worm.. .- 26 

Corn Root Worms - 22 

Cornstalk Borer -- -. 10 

Crop Rotation for Corn 43 

Deep Cultivation; Its After Effects on Corn 41 

Diseases — — 29 

Ear Scab or Ear Rot 32 

Explanation of Terms ..-. 10 

Foreword 5 

Insect Enemies.. 10 

Introductory and Foreword to Adjusters 7 

Seed Selection 37 

Smuts of Corn 33 

Stalk Fungus 29 

Summary of Losses to Corn — What to Look for and Where 
to Find It 45 

White Grubs 14 

Wire Worms 15 



LIBRARY OF CONGRES 



021 528 426 



iTROMOERG, ALLEN A CO., 



